OBJECTIVETo screen the learning and memory mutant from N-ethyl-N-nitrosourea (ENU) mutagenic zebrafish F1, and to get the new model animal to study the mechanism of learning and memory.

METHODSZebrafish mutant was screened by inhibitory avoidance behavioral test and identified by the expression of gene c-fos with qRT-PCR.

RESULTSWe isolated a zebrafish mutant related to learning and memory, fgt. In this fgt zebrafish mutant long-term memory was much lower than that in wild-type when tested at 24 h after training. The 24 h long-term memory in about half of fgt mutant F2 (13/30) were significantly lower than those in wild-type, and the others relatively normal. Compared with the expression in wild-type fishes, the expression of immediate-early genes (IEGs) c-fos in half of fgt mutant F2 (13/30) after exploring in a novel environment increased distinctly from the basal control levels statistically, and the others relatively normal, which were in accordance with the behavioral results.

CONCLUSIONThe zebrafish mutant fgt is a dominant mutant with defect in long-term memory.